In recent years, in the field of disk drives represented by a hard disk drive (HDD), a large-capacity hybrid disk drive has been developed, which uses a flash memory (usually, a NAND-type flash memory) which is a nonvolatile memory, in addition to a disk, as data storage media.
Furthermore, there has been developed a disk drive to which a method of using a disk including a shingled write recording area, which is an area with a high track density (TPI), and a media cache area, which is a recording area with a relatively low track density (TPI), is applied. Hereinafter, the shingled write recording area is referred to as “SMR (shingled write magnetic recording) area”.
Specifically, in the disk drive, write data from a host is stored in any one of data recording areas, namely an SMR area on the disk, a media cache area on the disk, and a flash memory.
The three data recording areas have different degrees of influence due to a variation of an outside environment, which represents an environment of the outside of the apparatus, such as vibration (impact), temperature, or atmospheric pressure. Accordingly, control is required to properly store write data, based on the variation of the outside environment.